Worksheet5 - Iowa State University

Phys 221 SI Worksheet:
Circular and relative motion
Supplemental Instruction
Iowa State University
Phys 221
1. The equations that describe the one dimensional motion with a constant acceleration are:
𝑣 = 𝑣0 + 𝑎𝑡
𝑥 = 𝑥0 + 𝑣0 𝑡 + 2 𝑎𝑡 2 𝑣 2 − 𝑣02 = 2𝑎𝛥𝑥
What are the equations that describe circular motion with constant angular acceleration
and how do they relate to the one dimensional motion equations?
2. An object moving in uniform circular motion has an angular velocity of 1.25 rad/s. What
radius is needed to have a tangential velocity of 3.75m/s?
3. For a radius of 1.5m and an angular acceleration of 2 rad/s/s what is the tangential
4. An object at rest begins to rotate with a constant angular acceleration of 5.0 rad/s/s. If a
point on the objects starts on the positive x-axis what angle does a line going from the
center of the rotation to the point make with the positive x-axis after 1.2 seconds?
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5. A wheel with radius 4.00 m is turning about a horizontal axis through its center. The
wheel starts from rest and undergoes constant angular acceleration in the
counterclockwise direction. Point A starts at the lowest point on the wheel. After 2.50s
the angular speed is 5.00rad/s. What are the magnitudes and direction of point A’s linear
acceleration when it is at the left most point of its trajectory after making ¾ of a
revolution, and the lowest point after making one revolution? How long does it take the
wheel to make 2 revolutions?
6. A boat must cross a 200m wide river and arrive at a point 120m downstream from where
it starts. To do so, the captain angles the boat 45 degrees upstream. If the boat can travel
4m/s in still water, what is the speed of the current? How long does the journey take?